ESOC

Rosetta swingby update - 03:13 CET 25 February

25 February 2007

At 03:13 CET today, Rosetta disappeared as planned behind planet Mars in the course of its critical planetary swingby manoeuvre, and, as anticipated, communication with the spacecraft was lost.

During this communication blackout, or occultation, planned to last until 03:28 CET, the spacecraft will have achieved closest approach with the Red Planet, at an estimated distance of some 250 kilometres from the surface.

The actual distance from the planet will only be confirmed tomorrow morning, when ground station ranging and distance data are processed and the exact spacecraft trajectory reconstructed.

Between 03:15 and 03:40 CET, Rosetta will be in actual eclipse – its solar arrays will not be illuminated by the Sun. During this phase, the spacecraft will have to live on the power generated by its on-board batteries, until the Sun rises over Mars' horizon and sunlight again hits the solar arrays.

Mission controllers at ESA's European Space Operations Centre (ESOC, Germany) will be able to definitively confirm the actual result of the swingby manoeuvre when the first house-keeping data is received on the ground, expected to happen at 03:58 CET.